Nothing is perfect. Or at the very least, nothing subjective is ever perfect.
I can't think of any TV series episode which I consider perfect (and I've seen the ones you've listed, and many more), everything has faults, highs and lows. This episode, to me, was the best of the season and therefore naturally also one of the best in the series following the latter half of season 1, which is where it peaked for me, so far. Given that, and given that it stands as high above the tv norm as it does, I feel that a score of 10 is justified.
Simply put, I scored it on a relative scale, not an absolute 'logical' one.
As previously stated, I don't think Game of Thrones is the best thing on television. We've had True Detective (which you yourself listed) which, in my opinion, easily claims that title for this year. Furthermore, not unlike yourself I too am irritated by the crowd which speaks of GoT as the greatest thing ever, blind praise and overhyping bothers me almost as much as snide elitist negativity does. I don't think I've displayed the former in my comment.
My issue isn't with people not praising the series, it's perfectly understandable that some might not enjoy things to the extent or in the way that I do. Just as an example, the setup scene with Roose and his bastard was fantastic for me because it really felt that I, as an audience, was right there in the wind-swept vastness of the north and every shot had this authentic look and weight to it. It was a short and relatively minor scene, but I just loved it.
There is a great span of grey between the radiant white that the fandom of the tv adaptation hype, and the darkest of blacks that some people on these boards claim the series to be. The primary reason why the latter does irk me a little more is because to me it means that people are missing out on great television, the praising fans don't deny themselves much beyond their critical thinking.